نشریه محیط زیست طبیعی
سال شصت و سوم شماره 4 (زمستان 1389)

Rivers are one of the most valuable aquatic ecosystems that their physiochemical properties and the biology of their organisms have strong interactions. One of the major rivers in Iran, which covers a variety of ecosystems, is called Tajan River. In this research, the effect of different pollution sources on water quality of this water body was investigated. Samples were collected in seven different sampling seasons (with three week intervals), which had been selected based on agricultural activities in the study area. The levels of nitrate, nitrite, phosphate, ammonia, dissolved oxygen, hardness, alkalinity, pH and BOD5 were measured. The results showed that the concentrations of phosphate and ammonia were much higher than the global standards for river environments. High levels of alkalinity and hardness observed in this river can be useful for the ecosystem health. The levels of other parameters were within or lower than the global standards. However, BOD5 showed higher levels than these standards in some stations.

This study was performed in order to provide a strategic development plan for ecotourism in Shahdad District of Kerman Province. Thus cultural, historical and natural attractions of the region and its surrounding areas were studied and identified initially. By completing Clawson Questionnaire in the form of Travel Cost Method (TCM), valuation and analysis of ecotourism demand index of the considered region was carried out. Considering the mentioned aim a number of 220 Clawson questionnaires at the time of maximum recreational demand (March, 2008 till April, 2008) was filled out in the study area. Based on performed calculations the recreational value of Shahdad District of Kerman was estimated equal to 5,698,250,000 Rial per month at the time of the study. Subsequently in order to compiling and presenting the quantitative strategies of ecotourism development the strategic planning method of SWOT was applied. This method is based on identification of internal factors (Strengths and Weaknesses) as well as the external ones (Opportunities and Threats) of the under studied area. In this regard the internal and external factors were specified using Delphi Method. After identification stage, the internal and external factors were arranged in the form of Internal Factors Evaluation (IFE) and External Factors Evaluation (EFE) Matrices and then scoring and weighing of the mentioned factors were carried out using EXPERT CHOICE Software and Analytical Hierarchy Process Method (AHP). The results obtained from noted above matrices were confirmed that despite the existence of unique natural and cultural attractions which potentially can convert the region as recreational pole of desert areas of the country due to deficiencies like lack of infrastructural facilities, failure introduction and advertising, the under investigation area is placed in competitive situation (ST Strategy). Moreover with the aim of integrating and scrutinizing information derived from internal and external evaluation, the Quantitative Strategic Planning Matrix (QSPM) was implemented. As regards the results of the noted matrix three strategies were suggested which among them the attraction of private sector investment through banking facilities with long return periods, national wealth transfer in the form of ninty-nine years documents with score of 5.12 were recognized as the most important strategies of ecotourism development in the region over a twenty year period.

Habitat associations of wild sheep, Alborz red sheep (Ovis orientalis gemelini X Ovis orientalis arkali), in Khojir and Sorkheh Hesar National Parks were studied over three seasons (Spring, autumn and winter) in 2000. The position of observed maternal groups (including ewe with lamb) and male groups (including rams, barren ewes and juveniles) were determined on topographical maps during the field work. Then, the prepared maps were digitized. Maps of slope, aspect, altitude, soil types, vegetation density, vegetation density of higher than 50 cm, density of forbs, distance to escape terrains, distance to water source and position of asphalted roads, tracks, paths and rural areas were digitized. The frequency of occurrence and density of different observed groups were compared among the classes of each information layer via Geographical Information Systems (GIS). Habitat suitability maps were subsequently prepared. The assessment of prepared maps indicates a logical relation between habitat suitability maps and filed observation Results suggest that wild sheep frequency has a relationship with slope and aspect. Notable aspect of preference of wild sheep is often eastern. In spring, male groups prefer the eastern aspect. Distribution was higher in soils with abundant gravels and high permeability. Abundance and density of wild sheep increase with density of total vegetation and forbs, and also vegetation taller than 0.5 meter, although the latter is not related to the increase of the ewes with lamb's Distance. Analysis shows a decrease in wild sheep abundance when the area is far from water sources and escape terrain and wild sheep are rarely seen to 500 meters from roads and 1000 meters from rural areas.

Landscape ecology as a modern interdisciplinary science offers new concepts, theories, and methods for land evaluation and management. A main part of landscape ecology is describing patterns in the landscape and interpreting the ecological effects of these patterns on flora, fauna, flow of energy and materials. Remote sensing and GIS techniques have a high ability for landscape researchers to specify maps and analyze landscape patterns. We can use the trends in indices to our management decisions. In this study, landscape patterns were quantified by the number and size of land cover patches, the degree of naturalness, and the diversity indices were calculated by GIS approaches and compared for 35 years, in order to reinforce the management efforts of Mouteh wildlife refuge in Iran. The results showed increasing destructions with regards to unplanned human activities, while some natural landscape improvements occurred in the core protected area.

In order to investigate variations in plant diversity in Dr. Dorostkar's forest reservoir, located in Gisoum Talesh, 44 sampling plots were applied by the randomized-systematic method. The diameter of all tree species (dbh?5 cm) was measured in 400 m2 (20×20 m) square sampling plots. In addition, the number of individuals of shrubs and saplings (DBH?5 cm) were enumerated in circular 100 m2 sampling plots. The cover percentage of the herbaceous species was identified by minimal area method using the Domin criterion. The indices of biodiversity, including Shannon-Wiener (H?), Simpson (1-D), Hill’s N1 and Hill’s N2, indices of evenness, including Shannon-Wiener and Simpson and richness indices, including Margalef and Menhinick were applied on tree, shrub, regeneration and herbaceous layers separately. The Species Important Value (SIV) of vegetation cover indicated that tree, herbaceous and regeneration species had lognormal distribution and shrubs species had geometric distribution in this area. Results showed plant diversity were low, due to Box tree (Buxus hyrcana Pojark.) which is shade tolerant. The diversity and richness were highest in herbaceous layer and decreased from herbal to tree, regeneration and shrub species, respectively. The highest evenness was found in tree layer.

The aim of this study is to investigate the tree specie's diversity in a region with no management planning and introduce the calculated indices as the norm for sustainability assessment. DBH of all tree individuals, and their stories were recorded in the inventory grid (75 m × 100 m) sample plots. Subsequently, richness, evenness (Simpson, Smith & Wilson) and heterogeneity (Simpson, Shannon-wiener and N2) indices were calculated. The richness index shows decreasing trend from the third story to first one. The heterogeneity indices increase from the third story to second and then decreases to first layer. These indices were calculated for the study area and also for each story, separately. Among the evenness and heterogeneity indices, Smith & Wilson and N2 showed the highest CV, respectively. Since one of the criterions in assessing forest sustainability is comparability of specie's diversity in managed forest and natural woodlands, so, specie's indices in the unmanaged region with natural state are proposed as a tool to evaluate forest sustainability.